Because there are practical limits to the pulse power from a single laser as well as limits to the pulse rates that can be achieved, it is desirable to combine beams from a plurality of separate laser sources into a single pulsed beam. Devices for combining beams from a number of sources or for splitting beams from a single source have generally employed beam splitters or semi-reflecting plates. In the case of beam combining systems, such a plate is used to reflect one beam along a path while allowing a beam from a second source to be transmitted through the plate along the same path. Such devices, however, are inefficient in that the beam splitter cannot reflect all the energy from the one source and transmit all the energy from the other source in combining the two beams.